


happy borth kaiba seto

by SheepySeconds



Category: Yu-Gi-Oh! Duel Monsters (Anime & Manga)
Genre: Birthday Party, Fluff and Crack, Fluff and Humor, Gen, I Wrote This Instead of Sleeping, Post-Canon
Language: English
Status: Completed
Published: 2019-12-10
Updated: 2019-12-10
Packaged: 2021-02-26 00:41:55
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 5,638
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/21744694
Author URL: https://archiveofourown.org/users/SheepySeconds/pseuds/SheepySeconds
Summary: Five years after the end of canon, Mokuba attempts to throw a party for his brother, and by 'attempts to throw a party' he means 'the party is a prank for his brother, who has never accepted the concept of birthdays as a whole'.So, to be fair, the resulting mess is at leastpartiallypart of the plan.
Relationships: Kaiba Mokuba & Kaiba Seto
Comments: 12
Kudos: 34
Collections: Yu-Gi-Oh! It's Time to G-G-G-Gift! [Mini-Exchange]





	happy borth kaiba seto

**Author's Note:**

  * For [twelvemagpies](https://archiveofourown.org/users/twelvemagpies/gifts).



> Prompt: "Mokuba enlists the gang in planning something for Seto's birthday. They think it's out of the goodness of his heart but actually, Mokuba's paying Seto back in his own coin in their decade-long prank war that Seto is absolutely not winning. Absolutely nothing (the plan, the prank, the party) goes the way it's supposed to."
> 
> I hope you like what I came up with! (And I had a _lot_ of trouble choosing between your prompts, let me add, because MAN, you had some good prompts!)

“So wait,” Jounouchi says. “You’re tellin’ me it’s Kaiba’s birthday, comin’ up.”

“Yep,” says Mokuba.

“And you’re sayin’ you want _me_ to help out setting up the party? Me? Jounouchi Katsuya? That me?”

“What am I,” Honda says in the background, “chopped liver?”

“Me,” Jounouchi repeats. “ _Me._ ”

“I thought you were at least intelligent enough to figure that much out,” Mokuba says. “I already got Yugi and Ryou to agree, and Anzu, and even Otogi! But it sounds like it’s probably going to be a bit too difficult for you, isn’t it?” Mokuba smiles, a hint of sadness in the curl of his lips. “I was hoping to get help from some of the people who know my brother best to plan this party.”

“Me?” Jounouchi repeats again.

“Yes, you,” Mokuba says. The brightness in his voice is beginning to strain a bit. “I don’t need to say it a fourth time, do I?”

“No, no,” says Jounouchi, as something unholy lights up in his eyes. “You don’t need to say anything. I’ve got this. I’ve got it in the _bag_. Kaiba’s gonna have the _best fucking birthday party of his life_ , just you fucking wait!”

Mokuba smiles. Jounouchi pumps his fist in the air, the unholy gleam still in his eyes, and grabs Honda by the shoulders. The blonde then starts running off with his long-time friend, babbling about ideas. All of them are, of course, terrible. Far too obvious. Yugi will at least temper the boy down to something less _obviously a prank_ when Jounouchi talks to him. Even after that, it would easily be traced back to Jounouchi. The better question is: since Mokuba had nothing to do with the ideas themselves, would Jounouchi give away the fact that his inevitable prank would trace back to Mokuba?

Eh, probably. But by the time Seto realizes _who_ had set the friendship brigade on him, it would be far, far too late.

This will be the best birthday party he’s ever participated in, ever.

* * *

It had started like this:

Every year, Kaiba Seto has a birthday. Every year, like clockwork, he ignores it. Mokuba can vaguely remember a time where he didn’t, mind you. It was at the orphanage. It was mostly because the caretakers forced them to celebrate it, and the caretakers always put on birthday parties that felt more empty than anything else. Mokuba was aware enough these days to realize the two of them were still too shell-shocked and surrounded by strangers to really let loose or open up back then, anyway. Then, later, once they were adopted, it was because their adoptive father thought birthdays were a weakness or something. Mokuba didn’t celebrate his own birthday during those years, either. He’d only made the mistake of trying to once.

Mokuba sometimes wondered about why the idea of birthdays were a weakness to Gozaburo. Were they supposed to have sprung, fully-formed, ready to design weapons and dragons for him? Or was it that they simply weren’t supposed to abide by the laws of such petty things as time and aging? Who knew. May the man rest in piss. Mokuba just wished that this defiance of humanity hadn’t occasionally passed down to his brother in the worst way.

Once Gozaburo had conveniently shuffled off this mortal coil (and, once again: rest in piss, my man), another few birthdays got skipped due to things such as: hostile takeovers, comas, strange Egyptian men wearing puzzles shouting about duels, and his brother having the emotional intelligence of a lemon. Once their life had calmed down, though? Mokuba had figured, hey, birthdays would be a great way to stick it to an awful man with an awful idea of what family was and help Seto relax in the process.

Instead, Seto had vanished to _space_ for a week.

This, naturally, meant war.

There is something liberating about going to war with his brother, and having it be over pranks and silly things. Normally, Mokuba is the main instigator. His brother normally reacts. Sometimes, Seto instigates—normally, when Seto instigates, Mokuba is forced to bow down to the older Kaiba. Like, for example, the light show thing at Kaiba Corp a month ago. The light show. With all the specific imagery that the crowd thought was lovely but Mokuba and, unfortunately, _also his friends from university_ had realized were incredibly, incredibly targeted inside jokes. His university friends had been mildly horrified. Mokuba had been resigned. One of them had told him they’d never thought they’d feel sorry for someone who had the most powerful man in Japan as their brother, and yet they were. Mokuba had nearly punched them.

_Anyway._

The point is? It had started a long time ago, with birthdays that they weren’t allowed to celebrate, and then with birthdays that Seto _refused_ to celebrate. It turned into longstanding prank wars and now, age eighteen, Mokuba is aiming for the ultimate prize: Seto’s birthday.

He’s going to throw Seto a party he can’t avoid.

It will be _beautiful_.

* * *

Mokuba doesn’t hear about the plans in the works for a bit longer than he would have preferred. It’s a bit anxiety-inducing, but he _had_ assured Jounouchi he did not need to tell him about the plans that apparently the man was now spearheading. (Mokuba shuddered in both anticipation and fear when Yugi said that he was officially too busy to lead the operation.) He’d told Jounouchi and Honda to spare no expense.

On Monday, he’s sent Bakura Ryou, who serenely smiles and says that he’d gotten his invite to the party and was flattered, and before Mokuba could ask about the blood, left. (The blood probably wasn’t concerning, given that Mokuba knew Ryou ran a very successful ghost-hunting show, and yet. Every time he saw Ryou, he grew more terrifying.)

On Tuesday, he’s send Otogi. Otogi looks harried. Otogi asks what Seto’s favorite variety of cake is. Otogi then asks if Mokuba would have the budget for a very, very large cake. Mokuba, baffled, reiterates to spare no expense. Otogi whimpers. Otogi leaves again.

On Wednesday, Mokuba runs into several members of the planning committee. The first are Anzu, who looks apologetic, and Shizuka, who looks even more apologetic. They’re holding massive quantities of wrapping paper and… Mokuba stares for several minutes.

“Are those all of the dragon action figures from the craft store?” he asks, just to clarify.

“Yes,” Anzu says.

“And is that… are those all diorama kits?”

“Yes,” Anzu says again.

Mokuba nods and sends them on their way. He assumes that will be the last of the weirdness for Wednesday. It’s not. Honda calls him to reserve a large convention center at Kaiba Land. This, at least, isn’t actually _weird_ , it’s just more contact with one of the friendship brigade. Then Jounouchi calls and rambles about guest lists. Mokuba smiles and nods and tells him that the guest list is, in fact, up to them, with the exception that Mokuba has to be invited, as does Yugi. Ryou calls again to say that he’s done a passthrough of the convention center and it’s not too badly haunted. That’s a slightly terrifying statement, but okay. Then Seto calls Mokuba in for an emergency meeting and Mokuba puts aside party planning for the day.

On Thursday, Pegasus calls to thank Mokuba for the invite, and Mokuba wonders if he should have maybe paid more attention to Jounouchi’s guest list.

“Mokuba,” Yugi asks on the Friday of that week. He looks exhausted. This isn’t unusual; Yugi has looked somewhere between exhausted and exasperated at least two-thirds of the times Mokuba has seen him over the past five years. “Mokuba,” he says again, and, ah. That’s actually more of a bad sign. Mokuba knows he’s actually in trouble when Yugi says his name twice. “I appreciate your trust in helping me to plan a party for your brother—”

“Aw, you don’t have to thank me,” Mokuba chirps, “you haven’t become indispensable here for nothing~”

“—and I appreciate you allowing me to plan with my friends—”

“I just thought they’d also appreciate a chance to tell my big bro what was good in the world,” Mokuba continues, bright and cheerful and full of shit.

“—but first,” Yugi says, “it has hit me that I have worked here for five years, and your brother is notoriously absent on his birthday.” A pregnant pause.

“Yes?” Mokuba says.

“Mokuba,” Yugi says a third time, and… okay, look. Mokuba answers to no man not named Seto, but after five years of being the only person anyone went to at Kaiba Corp when they needed the brothers to do something urgently, Mokuba had gotten a bit of a pavlovian reaction to Yugi saying his name like that, “why are you trying to convince the staff your brother’s birthday is ten days later than it actually is?”

“I—that’s just the date of his party—”

“Mokuba, you _changed his Wikipedia page._ You hacked the editing software of Wikipedia so no one could fix it _back._ ”

“I… thought it was funny?”

“You thought it was funny.”

“Yes.”

“You have managed to convince Jounouchi that Kaiba-kun’s birthday is on the _wrong day_.”

“Did I? Wasn’t very hard then, was it?”

“Mokuba.”

“Shutting up.”

Yugi runs a hand through his hair anxiously. “Your brother isn’t gonna notice you’ve been messing with his Wikipedia page, right? Because if he realizes you’re trying to reschedule the office around having him actually be around for his party for once, a lot of hard work we’ve all put in is gonna go to waste.”

For a moment, Mokuba feels like cheering. You see, this was, by far, the most dangerous part of the plan. Most of the people Mokuba had corralled for Seto’s birthday? Yeah, they wouldn’t notice how far out of his way he was going to make them throw the party on a date that Seto wasn’t expecting, to get people to assume that Seto had legally changed his birthday or something and was now throwing a party at a weird time. But Yugi? Yugi was the most likely to _notice_ , since Yugi turned up every year, like clockwork, with dragon-shaped cookies for Seto’s birthday that Seto tragically was always absent for.

(Mokuba always ate all of them. His brother was missing out.)

He was also the most likely to realize that Mokuba probably wasn’t going to such _extreme_ lengths solely out of the goodness of his heart, to realize that Seto absolutely did _not_ know this party was happening, despite Mokuba’s insistence to the contrary. Yugi was, in other words, the most likely to realize that this was all a prank.

“He’ll be there,” Mokuba says, “don’t worry. My big bro will have a party like he’s never had before!”

“I’m glad,” Yugi says. “Mokuba?”

“Yes?”

“Stop hacking innocent nonprofit encyclopedias.”

“I can neither confirm nor deny—”

“You absolutely can, and you know it,” Yugi says. “Also, please tell people to stop calling _me._ I’m just a game developer. I’m not involved in the management of your company. I am not a member of upper management. I am not a direct channel to the president of the company. I am a _game developer._ I have a degree in _game design,_ not business.”

“Okay,” Mokuba says.

(They have made this exchange approximately once a day for the past five years. Mokuba thinks they’re finally wearing Yugi down.)

* * *

By the time the actual party arrives, Mokuba is delighted to realize that he knows very, very little about what is actually going to _happen_. He’s arranged for surprise transportation for Seto, at least, but he hasn’t the _slightest_ idea what’s about to actually go _down_ inside that Kaiba Land convention center.

Some would consider this a dangerous way to run a prank. Mokuba considers it the ideal way. It could not be _easier_ to claim plausible deniability, after all! Besides, he made sure, after one more day of confusion, to get an in-road with Yugi. He made Yugi promise to tell him if there was anything Yugi was truly concerned about. This meant Mokuba would hear about anything he needed to take direct control of in any way. This also meant Mokuba was _beyond_ ready to see all of the things he wasn’t actually prepared for.

Some of the stuff he’d signed off credit card charges on…

First, however, was the difficult step of getting Seto into the convention center in the first place. Yugi had refused to plan a fake business meeting, mostly because he was still insisting that wasn’t his department (hah). Unfortunately, without Yugi, Seto would just ignore business meetings he wasn’t interested in.

(To be fair, so did Mokuba. This was why they had an Isono and a Yugi.)

Fake business meeting wouldn’t work. Fake card game tournament was also out, because Mokuba just isn’t that mean. Telling Seto there would be Duel Monsters and then not actually having Duel Monsters felt like kicking a baby puppy.

But Mokuba had a plan. So, he walks up to Seto.

“Nii-sama?” he says.

“Yes, Mokuba?”

“There’s a big event at the convention center at Kaiba Land today.”

“Mhm?”

“And it’s… you know that program I wrote last month?” Mokuba had written several groundbreaking programs in a month. He relied on the fact that, even though Seto was normally very, very good at keeping track of his little brother, the vagueness would make it impossible for Seto to remember if Mokuba had written anything of particular note.

“Yes?” Seto says, as though he knows exactly what Mokuba is talking about. _Success._

“Well,” Mokuba says, “they’re gonna be showing it there! And I’ve gotta make sure they don’t screw anything up when they do.”

“Okay,” says Seto, now looking rather annoyed. It’s a sharp expression. He knows exactly what Mokuba is going to ask nest.

“Nii-sama?”

“Get to the point.”

“I’d really, really like it if you were there to see it in action… It really is a good system to reduce the operating load by high-end AIs, allowing them to be run on—”

“Okay,” says Seto, before Mokuba can go on. Seto has always been more of a hardware man. Mokuba will exploit that relentlessly too. His brother is glaring at him. He knows that he’s being manipulated, like an idiot.

“Yay!”

“Mokuba, be more subtle,” Seto admonishes.

“Nope,” says Mokuba, “you’re terrible at subtlety.”

“You won’t get anywhere with the shareholders if you’re that blunt trying to manipulate them,” Seto says, letting Mokuba guide him out of the building and to the waiting limo, where Isono is trying very, very hard not to look guilty.

“I thought it’d be mean right before you vanish for your birthday,” Mokuba explains.

“No attempt to get me to a party this year?” Seto asks.

“Nope,” Mokuba says, his voice totally even. Seto narrows his eyes. “I mean, it never works, so I thought I’d give up for the year.”

“Mokuba, subtlety,” Seto says again. Mokuba carefully doesn’t smirk, instead pouting as the car starts moving.

“Aw, but I really _am_ giving up.”

“And better lies,” Seto says.

The car’s already on its way to the convention center. How’s that for subtle, Kaiba Seto.

* * *

That stuff about subtlety? Yeah, Mokuba takes it all back.

He and his brother and Isono all stare at the entrance to the convention center. It’s covered in glitter. There is so much glitter. Like, holy shit, there is so much glitter, Mokuba doesn’t even really know how to begin. He’s pretty sure he won’t be able to open the doors without just being utterly showered with glitter. Defeated by glitter. Destroyed by glitter. There’s even what appears to be a string-pulled bucket over the door that is, presumably, also filled with glitter. It’s blue and silver. In massive letters along the outside of the building, to says: _HAPPY BIRTHDAY KAIBAMAN_. Or at least, Mokuba thinks that’s what it says. It’s hard to tell; the glitter may have blinded him.

“Mokuba,” Seto says, before falling quiet. He opens his mouth. He closes it again. Glitter quietly shakes from the doors onto the ground. Mokuba would be cheering having managed to drive his brother of all people silent if it wasn’t also accompanied by he, himself, also being rather speechless.

Someone slams the doors open. Glitter goes flying everywhere. “IF IT AIN’T THE MAN OF THE HOUR!” someone shouts, and, oh, it’s Jounouchi. He’s wearing a massive smile. “KAIBA! You’re here just in time! We were beginning to think you weren’t going to show up.”

“Mokuba,” Seto says again, and huh. People have been doing that with his name a lot recently.

“I have to say, you’re gonna have a real gem of a time! You’re never going to have had a party like this one!”

“I can _see that_ , mutt,” says Seto.

“I bet!” says Jounouchi, entirely unphased. “Why don’t you come in? Everyone’s in full swing! No one’s gonna have a bad time tonight, let me tell you!” He laughs. Seto isn’t laughing. Jounouchi comes around, swings an arm around Kaiba’s shoulders, and thumps him on the back. There is something malicious in that expression.

Mokuba wonders, with idle, detached curiosity, what kind of storm he’s unlocked here.

“Is that _so_ ,” Seto says.

“I guess we better go in!” Mokuba says, and while those unfamiliar with his brother probably wouldn’t recognize it, Mokuba can recognize the betrayed expression any day.

“Yeah!” Jounouchi shouts, and he starts practically shoving them through the open doors. Mokuba starts coughing, because to get through the doors, they have to walk through a veritable _cloud_ of the blue-and-silver glitter that Jounouchi has purchased. Once they get _inside_ the convention center… well.

So, first, there’s the cake. It’s large, and covered in white icing, and has the Kaiba Corp logo crookedly drawn along its side. It is, true to what Mokuba had been told, absolutely massive. Hard to miss. Directly in the center of the room. And the room… there is an entire wall of complicated, artsy dragon dioramas. They’re so lovingly crafted that Mokuba could almost believe they _weren’t_ there just to make fun of his brother while _pretending_ to decorate according to his interests. The walls that don’t have dragons are covered in streamers and papercraft dragons. In the back of the convention center, there is a pile of presents.

Mokuba knew his present was hidden somewhere in the pile, too. He'd sent it early, as to not give himself away.

The lights are dim, and there are about three disco balls of clashing colors hanging from the ceiling. One, Mokuba is mystified to discover, projects white dinosaurs across the room. Maybe it was the closest thing to a dragon disco ball Jounouchi could find…? The other two are a red and green disco ball that occasionally strobes and makes everyone in the room flinch and a rainbow disco ball that seems to be synched with the eclectic selection of techno music.

The music, at least, is entirely tolerable. Mokuba had sent Jounouchi a playlist. As funny as whatever Jounouchi and the gang would have come up with for the music would have been, Mokuba was only willing to play with fire but _so_ much.

“Welcome,” says Jounouchi, “to the party of the century! Make yourself at home,” Jounouchi says.

“Mutt,” Seto says, “I can think of absolutely nothing I would rather do _less._ Really, impressive job. You’ve made an ideal hell for me.”

“Hey,” says Jounouchi, “I bought enough weird dragons.”

“This is why you’re hired muscle at best,” says Seto.

“I teach public school!” Jounouchi protests.

“Oh, I know,” Seto says.

“Well, you’re gonna appreciate my hard work, you got that, moneybags? I’m not even the only one who had to do stuff, you hear me? All of my friends had to work on this too!”

Mokuba can’t help but marvel. Did Jounouchi… actually take pride in the party? Because for a moment, Mokuba believes it. Then, Mokuba remembers that Jounouchi will get offended at anything Seto says, and the world is righted again. Ah yes. That’s right. Jounouchi wasn’t taking pride in how good the party would be, Jounouchi was just offended Seto didn’t like it, despite that being the _point._

“Oh joy,” Seto says, “the friendship brigade too.” Seto glances over the guest list. Mokuba realizes he doesn’t know where half the guest list is, but he can spot Pegasus, who is happily the center of attention. Most of the guests he can see are either fellow Kaiba Corp employees or what appear to be a poor confused but delighted park guests. “That makes me want to stay here _even more_. What’s next, a speech about the Heart of the Cards?”

“I’ll have you know those are forbidden words at this party!” says Jounouchi.

“…are you serious?” Mokuba interjects, because he can’t help it.

“Yeah, because this is a party for the asshat rich boy, so I decided we should at least do that much for him.”

“I’m _flattered,_ really,” says Seto, sounding anything but. “Mokuba. Lets go.”

“About that,” Mokuba says.

“ _Mokuba_ ,” Seto says.

“I might have already had the car driven away.”

“Then let's get a new one! Isono.”

“Sorry, sir,” Isono says. He sounds genuinely, genuinely sorry. “You’ve been outvoted.”

“How have I been outvoted at my own company?” Seto asks.

“Mokuba-sama said you would need to stay at the party, and, sir, you’ve told me before that Mokuba’s vote should outweigh yours unless its an emergency.”

“Fine. Fine!” says Seto. “I will stay at your… _birthday party…_ but only to see how _pathetic_ it truly will be.”

“Ohhhh, just you wait, Moneybags,” says Jounouchi. “This is gonna be a party like you’ve never fucking seen in your life!”

* * *

The next half hour is tense.

Mokuba has made himself scarce, but he’s kept an eye on his brother. Mostly, people are dancing to the music and mingling, though Mokuba has discovered where Honda went. Honda is standing awkwardly in a back corner of the convention center that had been hidden by the cake. Honda is standing next to a pool to bob for apples in, a dart board, and a ring-toss.

“I put this here so your brother won’t find me as quickly,” Honda explains. That is, Mokuba thinks, pretty valid.

“Carnival games?” Mokuba asks.

“Jounouchi wants to try to get Kaiba to bob for apples,” Honda explains.

“Ah,” Mokuba says. “That’s not going to happen.”

“Yeah, I know.”

“Well, as long as you know.”

Mokuba has also spotted where Yugi is. Yugi is standing next to the refreshments table, signing autographs for the random members of the general public who had gotten into the party and generally just drinking a lot of punch. It has not nearly been long enough for the punch to get spiked yet, and Jounouchi wouldn’t spike it, anyway. Mokuba is still concerned by the amount of punch Yugi has already managed to drink.

Part of this is Pegsaus’s fault, because the moment Pegasus looks like he might have gotten Seto to consider blows, Yugi intervenes. He looks across the room to look Mokuba in the eyes. Mokuba decides Yugi will be getting another pay raise.

Anzu and Shizuka appear to be mingling happily. Mokuba has no problem with that. Occasionally, Shizuka goes to the complicated dragon diorama and starts re-adjusting parts. Mokuba also has no problem with that; the diorama probably has to be very, very complicated indeed, doesn’t it?

No, the problem is that Mokuba still doesn’t know where Otogi or Ryou are. Mokuba doesn’t know where they are. Mokuba doesn’t know where Otogi, one of the most dramatic people Mokuba has ever met, or Ryou, one of the most disaster-prone people Mokuba has ever met, are.

Mokuba is understandably rather worried.

“Has… anyone bobbed for apples?” Mokuba asks in lieu of worrying even more about where the missing people are. Isn’t that the point? Isn’t the whole prank supposed to be an over-the-top party for Seto?

“No,” Honda says.

“Oh, okay!” Mokuba says.

“A few people have done the ring toss,” Honda says. “One of them was Pegasus. He was weirdly awful at it. I think it may have been on purpose.”

“Oh, okay,” Mokuba says, a little less enthusiastically.

The speakers start playing “The Cha Cha Slide”.

As though possessed, everyone in the building stands up to start doing the dance. Seto stands in the middle. He looks horrified. As Mokuba dances, he wipes an imaginary tear from his eye.

He’s so, so glad he delegated on this one. He couldn’t have come up with this if he’d tried. Or if he’d paid someone. Jounouchi isn’t getting paid. Refunded for expenses, sure, but not getting paid. Mokuba wouldn’t dare put a price on this.

Also, wouldn’t dare _pay for it_ like man—

* * *

“MY DEAR HUMANS!” says Jounouchi over the microphone, but only after “The Cupid Shuffle” and “The Electric Slide” and, perhaps most horrifyingly of all, “The Hoedown Throwdown” have all played and had _some_ large portion of the crowd dance to them, normally right around where Seto had been standing.

(“My dear humans?”

“Jounouchi’s being inclusive, but Ryou got to him in the process.”

“Ah.”)

“WE ARE GATHERED HERE TODAY TO CELEBRATE THE BIRTHDAY OF KAIBA SETO.” He pauses. Everyone is awkwardly silent for a moment until Shizuka starts a loud wave of cheering in support. “SO EVERYONE, GIVE IT UP FOR THE BIRTHDAY BOY HIMSELF! KAIBA SETO, COME ON UP HERE!”

“You aren’t on a stage, dweeb,” Seto says, refusing to move.

Yugi cheers loudly. Everyone clears the space around Seto and cheers as well.

“NOW, I HAVE DECIDED TO HAVE A BIRTHDAY TRADITION FOR MY _DEAR FRIEND_ SETO. A WONDERFUL, TRADITIONAL BIRTHDAY C—”

The cake bursts open. Out of it, Otogi in a sexy dragon outfit.

Mokuba doesn’t bother to see how his brother reacts. It’s hard to, through the fact that he’s _crying laughing._

* * *

“Honestly,” Otogi is saying. Mokuba is standing with Otogi and Yugi by the refreshments table. Seto is too horrified to go anywhere near Otogi, which means that Seto won’t approach Mokuba to try to convince Mokuba that they need to leave. Which means that Seto will remain standing in the party with an expression of stubborn pride. Which means that Mokuba is free to see where else this party could _possibly_ end up going. “I think Jou is projecting about the whole ‘scalie’ thing. And while I have always wanted to burst out of a cake—”

“Of course,” Yugi says weakly.

“—I must say, no one in the movies ever makes it clear how _sticky_ it is. Hey, Yugi, do you think you could help me with that?” Otogi wags his eyebrows. Neither he nor Yugi last for much longer before they both break down laughing about the terrible innuendo.

Mokuba is unimpressed.

“No, but Mokuba, is this truly what you expected?” Otogi asks.

“Not at all,” Mokuba says. “It’s better.”

“Kaiba-kun will be getting you back for this,” Yugi says.

“You’ve known it was a prank the whole time,” Mokuba accuses.

“Oh yeah,” says Yugi. “You wouldn’t have let Jou be in charge if it was anything but.”

“That’s fair,” Mokuba says.

“Thank you for allowing me to be a part of this,” Otogi says.

“Curse you for making me be a part of this,” Yugi says.

“NOW EVERYONE,” Jounouchi is shouting from his central location near the destroyed cake. “ITS TIME FOR ANOTHER FANTASTIC PARTY ACTIVITY!”

“Kill me,” Mokuba hears Seto say.

“HAVE YOU ALL EVER PLAYED NEVER HAVE I EVER?”

“I can’t believe I’m letting this happen,” Yugi says idly. “Normally I stop Jounouchi from getting himself strangled.”

“BECAUSE ITS TIME TO COME HERE TO PLAY: NEVER HAVE I EVER! SETO’S PARTICIPATION IS, OF COURSE, MANDATORY—”

Before Jounouchi can finish his statement, however, something unexpected happens: the back door to the convention center slams open. It’s a door that leads to a supply closet. Out of the closet, Bakura Ryou, holding what appears to be charms intended for an exorcism. Ah. Mokuba is pretty sure that’s a bad sign. Everyone stares at Ryou. At least there’s no blood or other materials quite _that_ suspicious, but Ryou’s still looking pretty damn suspicious, between the wild hair, the anti-ghost wards, and the fact that he’s somehow covered in dirt in a Kaiba Corp facility. He looks almost like a ghost himself.

The glitter clinging to his hair somewhat breaks this impression, but still.

“Um, hello everyone!” says Ryou, cheerfully. “Sorry for interrupting the party, but it turns out I was a bit wrong about the ghost situation before! Sorry about that!”

Then, out of the supply closet, what appears to be a massive, angry ghost wearing a duel disk appears.

“You will pay… for daring to celebrate with cake in the place I once choked on a cake and died… I will kill all of you… who cannot beat me in a duel!”

Jounouchi screams, high-pitched and horrified, and falls over. Then, a terrible evil laughter. Everyone turns too Seto.

“ _Finally_ ,” he says, pulling out his duel disk. “I have been waiting _all night_ for something like this!”

* * *

After his brother is done dueling what his brother insists was a hologram, the party starts to fall apart. Oh, everyone had deeply enjoyed Seto absolutely _crushing_ the plausibly-wasn’t-a-ghost, but after the duel was over, most of the party-goers had realized, nervously, that this was the sort of thing that happened around a large concentration of duelists, and they’d left. Once the convention center was mostly empty of the non-duelists, Ryou began apologizing profusely.

“I thought I could add on to the party by doing something fun,” says Ryou, “but when I came in this afternoon to check on things, I accidentally got kidnapped by a ghost.”

“A crazed lunatic with a hologram,” Seto corrects.

“I closed the gateway to the underworld,” Ryou says.

“Oh,” Jounouchi squeaks, “of course!”

“But,” Ryou continuous, undaunted, “I couldn’t beat that last ghost. So thank you for beating it! I think it probably could have hurt quite a few people.”

“…I can’t for the life of me tell how serious you’re being,” Mokuba admits.

“It’s better not to ask,” Yugi says, sounding _disgustingly_ fond. And also disgustingly _suspicious_. Both he and Ryou are too good at keeping straight faces, though. Mokuba can’t decide how real or unplanned the ghost was. (Unlike his brother, Mokuba refuses to discount magic as a possibility at any moment these days.) He has to hand it them—either way, that outdid any of the other plans or pranks that had gone into the night so far.

“What do you actually do, Bakura-boy?”

“I run a popular ghost hunting show,” Ryou says.

Honestly, most days, the only reason Mokuba thinks Ryou _can’t_ raise the dead is because the Pharaoh would be back by now, either because his brother would have found out and insisted, or because Yugi would have used his excellent kicked-puppy look to get the man back.

“It seems like the party is dying down,” Yugi says. “Was there anything else on the agenda?”

“Nah,” says Jounouchi. “I was gonna play Truth or Dare, and maybe Cards Against Humanity, but… I think the ghost kind of took the energy out of things.”

“The presents?” Seto asks.

“I know you want to open them alone,” Jounouchi says. He looks away awkwardly. “Figure I tortured you enough in the name of the party. Happy birthday, man.”

“…sentimentality from the mutt.”

“Will you just _shut up and take it,_ ” Jounouchi says. “You can get the presents loaded up and go home if you want.”

“Then I will,” says Seto.

“Yeah,” says Mokuba. “Thanks for helping my brother have a good time!”

“No problem,” says Yugi. “Also, Seto? Next time you want me to tell you what your brother’s up to, you need to offer more paid time off than that. Bye!”

* * *

Seto opens the present from Mokuba in the car. Mokuba smiles at his older brother softly as he flips open what Mokuba had given him. It’s a photo book. Some of the photos are blank. A lot of them are of his brother’s friends (no matter how much Seto would protest they weren’t friends, he also hadn’t insisted Isono take them home, which meant that Seto had been, in fact, willing to put up with things). Even more of them are of the two of them. Some of them are of Seto alone.

Mokuba knows when he gets to the last page, because Seto’s shoulders slump.

“…Mokuba, you…”

The last picture is old, from the orphanage. Photos were always taken for birthday parties. They had been surrounded by people in that picture, but Mokuba understands now that they had been totally alone. But now. Seto’s white coat is covered in glitter. There are bits of birthday cake everywhere. His hands are still shaking with excited adrenaline. All of this from a birthday party that Mokuba had managed to pull everyone together to throw in about a month.

Mokuba figures that after a sentimental blow like that, Seto will take at _least_ a few days before planning his revenge for the party.

Seto reaches a hand over and runs his fingers through Mokuba’s hair before whispering: “I’m still leaving town for my birthday.”

“Already planned for that,” Mokuba says.

“This was terrible,” Seto says. “Just terrible.” And then he thumbs through the photo album again.

“The building didn’t burn down,” Mokuba says. “I’d say it’s a success.” He smiles brightly. “Happy birthday, Seto.”

* * *

When they make it back to the manor, Mokuba opens the door and immediately has a bucket of white paint dumped on his head.

“The classics, Mokuba,” says Seto, droll. “Be more subtle.”

Mokuba has no comeback for that.

**Author's Note:**

> some other notes:  
> the ishtars don't appear in this fic, but ishizu sent kaiba a passive-aggressive present that's like, simultaneously valuable and a veiled insult. they both enjoy this. she's across the world helping to start repatriating artifacts in museums. marik doesnt send kaiba gifts but he sends him a card sometime from whatever exotic location he's visiting this week. mokuba is uncomfortably certain that the rare hunters are way less disbanded than marik pretends they are, but marik seems to help people more than hurt with his organization so mokuba leaves it be. rishid sends something practical. mai shows up on kaiba's _actual_ birthday and complains to jounouchi about having not been invited to the only party kaiba's ever shown up to while jounouchi tries to explain that he wanted to spare her the potential drama.
> 
> everyone is pleased.


End file.
